in 30 litres of a solution 90% is alcohol then how much water needs to b added to make it 80%.

A mixture of 70 litres of wine and water contains 10% water. How much water must be added to make water 12 and 1/2 % of the total mixture ?

A mixture of 30 litres of spirit and water contains 20% of water in it. How much water must be added to it, to make the water 25% in the new mixture ?

A mixture of 45 litres of spirit and water, contains 20% water in it. How much water must be added to it to make water 25% in the new mixture ?

A solution of 165 litres contains 80% of acid and the rest water. How much water must be added to the above solution such that the resulting mixture contains 25% water ?

A solution of 150 litres contains 60% of milk and the rest is water. How much water must be added to the above about solution such that the resulting mixture contains 50% of water (in litres) ?

A vessel contains 60 liters of acid and water solution containing 80% acid. How much water in it to be mixed with 60% acid solution?